Lift trucks are designed in a variety of configurations to perform a variety of tasks. Most tasks include the operation of a vertically movable platform to lift and lower an operator and/or a load. Power for the operation of the lift truck, including motive power for the tractor unit and elevation and/or operation power for the platform, typically comes from energy stored in one or more large capacity rechargeable batteries, a fuel cell, or an internal combustion engine, or a combination of these power sources. The power source is typically located on the tractor unit of the lift truck.
Common methods of providing necessary power and control from the tractor unit to the platform includes the use of long lengths of wires that extend from the tractor unit through or on a vertically extendable mast or elevating mechanism to the platform. The mast typically consists of one or more rigid metal frames that are nested within each other like an extension ladder. As one or more of the mast's nested metal frames are extended or telescoped upward, the platform is raised. Threading wires in or on the mast is a complex design and manufacturing process. There may be bearings between the moving frames and the wires, and the wires must be placed within the sliding metal frames without interfering with movement. Placing of wires on or in the moving metal frames will, by necessity, require more space for packaging.
It would therefore be desirable to reduce and/or eliminate the need to route wires from the tractor unit to the platform, and replace the use of wires routed on the vertically extendable mast with a secondary energy storage device to provide power for the platform's power needs.